Merseyside Police on Operation Empower duty busted a drug deal after covert officers spotted it while filming an interview on Thursday night.
Earlier in the evening a number of plain-clothed and uniformed officers headed out into the city centre as part of Operation Empower - aimed at preventing serious incidents from happening by targeting people behaving in a predatory way.
While recording one of a series of videos filmed throughout the night, however, officers noticed the crime and took action.
Leading the operation, Sergeant Keeler explained: "Covert policing allows us to see things that normal officers in uniform wouldn't.
"The reason being is that sometimes perpetrators of drug offences and sexual violence crimes don't want to be seen and will move their activity away from streets where there is high visibility from policing.
"In non-uniform we can go to those alleyways and spot things from a distance and we can get closer to offenders before they see us."
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